When I was installing Mint Debian edition unlike the classic edition, the installation automatically formated my home partition when I did not specify to format.
So the formatting previously was ext4 ...

I have /dev/sdb1 and /dev/sdc2 that were previously setup into a RAID-1 with mdadm, but then I reinstalled and lost the old configuration. Out of idiocy, I ran
sudo mdadm --create /dev/md0 --level=1 ...

I've reinstall windows 7 on it's asignated partition and, as usually, it override the MBR with it's own stuff and, thus, it was not possible to boot to my ubuntu 12.04 partition.
I followed the step ...

I'm unable to mount my 300GB external (in external enclosure) HDD's single partition. None of the fsck tools add anything, they cannot even recognize the partition. I had forgotten whether I had used ...